My parents want to get a fourth gen fbody but its one of the LT1s with the opti-spark system. I hear alot of complaints about the optispark having problems due to coolant leaks from the w-pump. How bad is it as far as durability is concerned? Does it come down to maybe jsut replacing the water pump and opti-spark cam sensor at the 60k mark as preventative matenence or will it be more problematic then that? This possibly will be my parents car and not mine so they know nothing about cars or about how to make any repairs whatsoever so if they have alot of trouble with it ill hear things like: "You said this would be reliable!", "I should have never listened to you about these so called lt1 things being good motors.", and "I should have bought a Mustang GT!!!"

 

24/7,

I had one start to fail (misfires) for me at 110K miles. The sensors were not the problem so much as the cap and rotor themselves. I was able to remove the unit, clean the optical array and interruptor wheels, and replace the cap and rotor. The insulation in the cap had started to break down and allow cross-firing of some plugs.

The biggest drawback to the system is the difficulty in diagnosing and servicing it. With a "regular" distributor, we can easily replace the cap and rotor if they are suspect. For the Opti, it's not in the most accessible location. And being located in the front and under the water pump does present some risks for a unit that fails most often from moisture ingestion. If you keep your engine clean and leak-free, the Opti should last 100K without any problems.

Of course, any replacement cap should be the vented type to minimize moisture related problems that the early sealed units suffered. If you have a early model, you'll have to provide an inlet breather hose and vacuum hose and regulator to keep it vented, but those are readily available.

 

save yourself some trouble and get a 95 model or later. they use the vented opti and not the sealed ones use on pre-95 models. 96 and later used a crankshaft sensor (just more that can go wrong). as mentioned it a pain to access the dist since, as mentioned, it is located UNDER the water pump. it's good motor, just not for the un-mechancially inclined types.

 

I was in opti hell a few months ago....this is an area you are best off buying GM new parts....I had the full opti, cap /rotor and distributor..replaced. New waterpump, (do it now, needed or not) Plugs and wires...fresh synthetic....$1150.00 installed..850 of that was parts. I tried Ebay...got screwed...tried remanufactured...failed.
its a tough job to risk on substandard parts..

 

Look around at some of the late '90s Crown Vic cop cars, trailing a plume of oil smoke at less than 100K miles. Those engines aren't babied and are strained to move a tub like the Vic, and show their weaknesses early. Would that somehow be better than having to replace a distributor at 100K miles? That same 4.6L Tinker-Toy engine is stuffed into Mustangs.

Look at Mitsubishi's long history of head and valve train failures. Subarus's crankshaft failures, Honda's history of electrical problems, Chrysler's problems in general, and you'll see that there is no "perfect" vehicle. If you want a vehicle that can run a third of a million miles with little more than regular maintenance, it's very hard to beat the GM V-8s and Hydramatic transmissions. It may not be the latest technology with all the cupholders, map lights, and butt-wipers, but it works.

The same as the human heart. We don't give up on that old technology just because there's something new and improved. GM built the later Gen III V-8s with a very similar design to the Gen I for some very good reasons.

 

youre preaching to the choir with me, vader Ive seen those gm engines go through the unthinkable and live to tell about it. Such as my mom not changing the oil in her s-10 for 35k untill it ran out of oil and stalled. Or, my dad having a coolant leak in his 3.8L LeSaber a couple of years ago for the longest time (bad w. pump after 110k) and not bothering to say or do anything about it. All i hear is: 'Well, coolant leak stopped a week ago but the engine seems to be having an overheating problem. Wahts wrong???' Open up the radiator and of coarse, its empty. Ran without coolant all that time and its still going today with a 170k on the clock. After all that they still dont share the same enthusiasm that i do about gm. They seem to think that all the other crap out there can take just as much abuse as the gm stuff.